1. Field of the Invention
The present invention relates to an electrical connector assembly and a electrical connector element for use with a printed circuit board wherein the connector element or contact is removably secured to the printed circuit board and wherein each connector element is individually insulated by an insulator casting. In one particular, the invention relates to a connector assembly of this type in which a plurality of connector elements are included and which may enter the insulator casting from the top or bottom.
2. History of the Prior Art
It is well known that there are many methods of employing electrical connectors and connecting elements in operative relationship with printed circuit boards. Some methods involve permanent attachment of a connector element and the connector to the board. However, there are times when it is desirable to remove the connector from the board to interrupt a portion of the circuit and for this reason a permanent attachment may be undesirable. Other methods involve the use of connector elements (commonly and herein also referred to as contacts) permanently secured within an insulating casting. Replacement of damaged connector elements in this type of assembly is difficult or impractical.
It should be noted that connector elements may frequently become distorted or broken thereby disabling the connector circuit. Also an assembly with permanent connector elements physically exposed may give rise to problems of electrical shorting. Another problem is that these connector elements commonly are not separately insulated since during the process of securing them to the circuit board such as by welding the heat generated would be destructive of the synthetic insulating materials commonly available.
In those instances where electrical connector elements are disposed in an insulating casting some functional characteristics of use are involved which require careful attention in utilization of the component. For example, it is well known that materials from which insulating castings commonly are made have relatively low melting points. If leads are to be soldered to connector elements soldering temperatures of 500.degree.F to 700.degree.F may be realized. Temperatures of this order extend into the softening or destructive range of materials used in making insulating castings. It can readily be seen that a severe functional limitation is placed on any assembly of casting and connector elements.
Where reliability in circuit continuity is important in electronic devices it always is desirable to have a secure connection defined at circuit junctions. This commonly is realized by soldering such junctions to define positive mechanical and electrical connection.
However, a limitation is imposed where contact elements are joined to circuit boards if the elements are disposed in an insulating casting since the casting may soften or melt during soldering. For this reason, when contact elements are to be soldered to a circuit board they commonly are not provided with the protection of an insulating casting. The present invention is intended, in part, to provide a structure which permits soldering and also provides protective insulation for the contact elements.
The present invention also relates to an improved electrical connector assembly for use with a printed circuit board where the connector element may be easily removed from the circuit board and yet be capable of providing good electrical and mechanical connection and will securely hold the mating insulator casting to the printed circuit board. This connector element may easily be mechanically inserted and removed from the mating insulator casting and provides a simple means of economically achieving mechanical and electrical connection.